This list is mostly for my own benefit. I started it a few weeks ago, and have decided to put it online for easy access. When new movies make the list, I'll edit accordingly.
I did not include my favorite anime, documentaries, or TV shows. As you can see, my tastes are kind of geeky and/or sentimental. [More interesting than what's on the list, perhaps, is what I've left off.]
My top 50 movies are divided into three tiers. I had a top 10 (the first tier), a second tier of 10, and a third tier of 30. Within each tier, the movies are not ranked against each other (but are listed in alphabetical order, instead). The short comments are the same as my Netflix "Two Cents" reviews.
Tier 1 (10 movies):
The Adventures of Buckaroo Banzai Across the 8th Dimension
A quirky cult classic with colorful characters and a unique sense of style
Dune
Cult sci-fi. I grew up watching the extended version on TV
Faraway, So Close!
Poetic, beautiful, and moving. The source of "Raphaela"
The Good, the Bad, and the Ugly
Sergio Leone's direction plus Clint Eastwood's performance plus a great supporting cast = greatness
The Great Escape
Action adventure with memorable characters, brilliantly performed
Pollyanna
One of the most perfect movies ever made
The Right Stuff
An American classic
Some Kind of Wonderful
The perfect 80's teen movie
Tron
Extremely ambitious and visionary, with a great story to boot
WarGames
They don't make technothrillers like this anymore
Tier 2 (10 movies):
Battle Royale
A story of youth rebellion against a society that fears, torments, and uses them as an example
Enter the Dragon
The quintessential Bruce Lee movie, filmed at the height of his physical condition and ability
Harry Potter and the Sorceror's Stone
"It has all the magic and wonder of the original", because it is the original! (yes, I saw the movie first)
The Hunt for Red October
The first Jack Ryan movie is my favorite by far
Mr. and Mrs. Smith
A surprisingly nuanced and funny romance, enhanced by excellent action sequences and gunplay
On the Edge
Primer
Taut, well-written sci-fi on a budget
Red Dawn
You don't have to be a right-winger to be moved by this beautiful vision of near-future dystopia made in the 80's
Star Trek II: The Wrath of Khan
My favorite Trek movie; the soundtrack by James Horner is magnificent
Tomorrowland
What many critics miss about Tomorrowland: it's less about nostalgia for old visions of the future, and more about a revival of the spirit
Tier 3 (30 movies):
All the President's Men
The Andromeda Strain
Armageddon
Basquiat
Battlestar Galactica
A Better Tomorrow II
Breaking Away
Cinema Paradiso
Conan the Barbarian
Contact
Drumline
Fast Times at Ridgemont High
Gabbar is Back
Ghostbusters
A Knight's Tale
The Legend of Billie Jean
Love Actually
Margin Call
Music and Lyrics
Ocean's Twelve
Once Upon a Time in America
Once Upon a Time in China 3
Pi
Push
The Rock
Searching for Bobby Fischer
Speed Racer
Spider-Man 2
Star Trek IV: The Voyage Home
Until the End of the World
Honorable mentions (recently bumped out of the top 50):
The American President
Blade Runner
Cool Hand Luke
Crimson Tide
Great Balls of Fire
Hero
Kate & Leopold
Lara Croft: Tomb Raider
The Longest Day
The Outlaw Josey Wales
Papillon
Redbelt
The School of Rock
Taxi Driver
The Transformers: The Movie
Zoolander